Note: Descriptions are shown in the official language in which they were submitted.
2~~~9~~
DE LA RUE GIORI S.A. LAUSANNE/SWITZERLAND
Method for separating sheets of paper stacked in reams and
device for implementing this method
FIELD OF THE INVENTION
The present invention relates to a method for
separating sheets of paper stacked in reams of sheets by
applying the ream against a curved surface in order to
separate the sheets of this ream, especially printed
sheets, preferably loan papers, and devices for
implementing this method.
PRIOR ART
In Patent DE-B 2,641,214, such a device is
described for separating the reams of sheets. This device
is mounted in the path of the reams and is composed of at
least one pair of transporting rollers forming between
them a gap through which the reams of sheets pass, the
width of this gap being less than the thickness of the
ream, and the lining of at least one of these rollers
being made from elastic material.
The handling of paper in printing works
increasingly poses problems connected with the increase in
the productivity of the machines. Whilst considerable
efforts have been made in improving the various printing
phases, the operations for separating the sheets of a ream
before the latter is brought to a feed of a printing
machine or to another treatment device have remained among
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the poor relations of innovation. Thus printers still
handle currently by hand quantities of paper which daily
are measured in tons.
Between the various operations, buffer stocks of a
greater or lesser size are constituted, generally in the
form of reams or stacks, typically comprising 250, 500 or
1000 sheets. The transfer of these reams of sheets from
one treatment device to the next is generally performed on
palettes having several reams. Automatic palletizing,
l0 carriage guiding and automated storage systems are known
in the prior art. One of the main difficulties in
automating the chains of current devices for treating the
sheets of paper therefore results from the handling of the
paper in the transfer of the reams from the palette onto a
feed, while separating the sheets, especially the sheets
of loan paper. This operation is currently carried out by
operators who separate the sheets of a ream from each
other, by bending their edges, aerate them and jog them by
hand, before supplying the feed of the printing unit or
another treatment device.
The object of the present invention is to permit
the automation of the separating operation.
SUMMARY OF THE INVENTION
This object is achieved by virtue of a method in
which the ream is applied against a curved surface in
order to separate the sheets of this ream by exerting
pressure forces against the outer sheet of said ream along
at least one line of application parallel to the
generatrices of the curved surface, said line of
application is moved perpendicularly to the generatrices
of the curved surface over the entire length of the ream
and then beyond each of the edges of the sheets, thereby
releasing the sheets, the intensity of said pressure
forces remaining sufficient, during their movement, to
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keep the sheets against the curved surface, the speed of
said movement being adjusted so that the released sheets
successively move away from the remaining curved sheets,
thereby re-establishing a plane ream, and this formed ream
is jogged.
A device according to the invention for
implementing the above method, which comprises
- a jogging table comprising, in the middle, an
openable zone,
- a deforming cylinder located at some distance above
this table and the generatrices of which are substantially
parallel to the plane of this table,
- movable pressure means comprising at least two rotary
and movable separating rollers, the axis of rotation of
which is parallel to the generatrices of said deforming
cylinder, these rollers being installed in order to be
moved with respect to the deforming cylinder from an
initial position below the ream into said openable zone of
the table, over trajectories parallel to the surface of
the cylinder and in order also to be moved in the radial
direction with respect to said cylinder;
- control means for controlling the movements of said
separating rollers,
- means for insufflating air directed against the edges
of the released sheets parallel to the generatrices of
said cylinder and
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- jogging means.
Preferred embodiments of the method and device are
described in the dependent claims.
The device according to the invention therefore
ensures, after installing a ream on the board, the
following functions:
- separating the sheets of a complete ream (typically
500 or 1000 sheets) by slidino~ the sheets over each other,
during the deformation of the ream applied against the
deforming cylinder,
- aeration of the paper when the separating rollers
release the sheets, sheet by sheet, and when they land on
the board,
- shaping a ream by jogging against a rim of the board.
The shaping of the stack of sheets landed in a
ream of irregular outlines may be carried out by tilting
the board and jogging by a hydraulic system or by a cam,
or by any jogger known in the state of the art.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be better understood by
virtue of the description of a preferred embodiment and of
the figures which accompany it, in which
Figure 1 shows diagrammatically a view of a device for
separating the sheets in the phase of arrival of a ream
onto the board of the jogging table,
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Figure 2 shows the same device during the application of
the ream against the deforming cylinder arid the start of
the movement of the separating rollers,
Figure 3 shows the continuation of the movement of the
separating rollers,
Figure 4 shows the separating rollers close to their final
position and the landing of the sheets on the board,
Figure 5 shows the device during the jogging operation
with the mechanism for moving the rollers,
Figure 6 shows the device in the direction of the arrow F1
of Figure 5 during the transfer of the ream reformed on a
feed table.
The elements described are designated by the same
reference numbers in all the figures.
DESCRIPTION OF THE PREFERRED Et4BODIMENT(S)
The jogging table includes a board 1, composed of
stationary elements 11, 12, and of movable elements 13,
14, 15, 16. In the center of the board, the movable
elements 13 and 14 can take up a position aligned with the
elements 11, 22 and 15 in order to form a continuous
support for a ream R of~sheets, as shown in Figure 1, or
can be moved below the stationary elements 11, 12 in order
to leave an open zone 17 (Figures 2 and 3). Below the
center of the board 1 is a retractable part in the form of
a piston 2 and, on either side of the latter, there are
two rollers 61 and 62. The open zone 17 is sufficient for
allowing these rollers 61, 62 and this piston 2, which is
able to move in the vertical direction, to pass. The
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movable elements 15, 16 form, in their vertical position,
lateral walls of the board. The entire board 1 may be
tilted with the aid of a hydraulic jack 3 (Figure 5) which
lowers the stationary element 12.
A motor 5, fixed below the stationary element 11
and driving an unbalanced mass 6 which vibrates the board
1, is provided in order to jog the ream, after the
separating operation, in its position illustrated in
Figure 5.
The separating device 4 comprises a deforming
cylinder 41, mounted in a frame 42 (Figure 6) which
carries, on one of the sides of the cylinder 41, two jacks
44, 45 with their piston rods 48, 49 (Figures 5 and 6)
and, on the other side of the cylinder 41, two jacks 44',
45', with their piston rods 48' 49' (Figure 6). All these
jacks are mounted on the frame 42 so as to rotate about
the same axis, coaxial with the axis 43 of the cylinder
41, and are equipped, for this purpose, with journals 46,
46' and 47, 47' respectively, forming but a single
component with the casings of the corresponding jacks and
being perpendicular to the axis of the corresponding rod
48, 48' and 49, 49' respectively.
The journals 46 and 47 are housed in the frame 42
and are free to rotate by means of rolling bearings 50, 51
and 52, the bearing 51 in the middle being common to the
two jacks 44, 45. On the other side of the cylinder 41,
the journals 46' and 47' are housed in the rolling
bearings 50', 51' and 52', the bearing 51' in the middle
being common to the two jacks 44' and 45°.
The jack rods 48, 48' and 49, 49' carry, according
to Figures 5 and 6, separating rollers 61 and 62
respectively, which are free to rotate about their axes 63
and 64 and extend parallel to the axis 43 of the cylinder
41.
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For this purpose, the separating roller 61 is
equipped, on either side, with journals 65, 65' housed so
as to rotate in bearings provided in said rods 48 and 48'.
In a similar manner, the separating roller 62 is equipped
with journals, not seen in Figure 6 (hidden by the
journals, 65, 65'), these journals being housed in
bearings for the rods 49, 49' of the jacks 45, 45'.
Two motors, 55 and 56 respectively, fixed to the
upper part of the frame 42, are provided in order to drive
the jacks 44, 44' and 45, 45' rotationally. The journals
46, 46' of the jacks 44, 44' are prolonged by two pulleys
53, 53' driven by the belts 54, 54' of the first motor 55.
In this manner, the motor 55 can drive the jacks 44, 44'
about the axis 43 of the cylinder 41, driving the
separating roller 61 around the cylinder 41 on which it
rolls. In the example in question, the movement of the
motor 55 is transmitted to the belts 54, 54' by means of
two bevel gears 68 and of a transmission shaft 67 to the
ends of which pulleys 59, 59', receiving said belts 54,
54', are fixed. The same drive system is provided for
rotating the jacks 45, 45' about the axis 43 driving the
separating roller 62; this system includes the motor 56,
two belts 58, 58' and two pulleys 57, 57' fixed to the
journals 47, 47'. In the same manner, the transsmission of
the movement of the motor 56 to the belts 58, 58' is
performed by two bevel gears 70 and a transmission shaft
69 carrying, at its ends, the pulleys 60, 60'.
By virtue of this configuration, the rollers 61,
62 may be moved, on the one hand, in the radial direction
with respect to the cylinder 41 under the effect of the
jacks 44, 44' and 45, 45' respectively and, on the other
hand, about the cylinder 41 in the angular direction on
trajectories coaxial with the cylinder 41 and parallel to
its surface. These movements of the rollers around the
cylinder 41 may be simultaneous, preferably symmetrical in
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opposite directions, or independent of each other, the
movements being effected successively.
The essential phases of the separating, aerating
and jogging operations are shown successively in Figures 1
to 6:
In Figure 1, the e:Lements 13, 14 and 15 of the
board 1 are aligned with the stationary elements 11 and
12; the piston 2 and the rollers 61 and 62 are in their
low position. The ream R o:E the sheets is pushed in the
direction of the arrow F against the raised element 16
with the aid of the pusher P, thereby centering it
approximately below the axis 43 of the cylinder 41.
As shown in Figure 2, after the pusher P has been
withdrawn and the element 15 raised, the elements 13 and
14 are lowered and moved away from each other below the
board 1. Simultaneously, the piston 2, acting as a bearing
surface, holds up the ream R against the cylinder 41
serving as a guide for the rise of the two rollers 61 and
62 {Figure 2). The rollers 61 and 62 then lift up the ream
R, under the action of the jacks 44, 44~, 45, 45' and
press it against the cylinder 41 with a constant force.
When the two rollers 61 and 62 are holding up the paper,
the piston 2 is lowered again (Figure 3). Under the action
of the motors 55, 56, the roller 61 moves away from the
roller 62 in the direction of the arrow F1, whereas the
roller 62 moves symmetrically in the direction of the
arrow F2 (Figure 4). Under the effect of the deformation,
the sheets of the ream slide over each other, plane on
plane, on account of the difference in the radii of
curvature, which vary from the first to the last sheet;
their edges are thus offset, this offset being parallel to
the generatrices of the cylinder 41 and to the
generatrices of the rollers 61, 62.
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When a roller 61, 62 passes beyond the edge of the
last sheet, the latter is detached from the ream and lands
in the direction of the board, as shown in Figure 4. As
the movement of the roller continues, the sheets are
separated one after the other from the rest.
Simultaneously, or with a time delay, the same phenomenon
occurs on the other side, under the effect of the movement
of the second roller. Since the drop height in the central
part of the sheets is sm<~11 in relation to their
dimension, as shown in Figure 4, the sheets land on the
board 1, reforming a stack which is substantially
rectangular, although irregular. The method may be
accelerated, and the aeration of the sheets improved, by
insufflating air via nozzles 7 and 8 in the direction of
the arrows F3, F4, of Figure 4 between the sheets after
they have been detached from the rest of the ream pressed
against the cylinder 41.
At the same time, or after the sheets have
dropped, the board 1 is lowered on one side with the aid
of the jack 3 and the elements 13, 14 are closed; under
the effect of the tilt and of a vibrating movement created
by the unbalanced mass 6 rotationally driven by the motor
5, the ream R is jogged against the raised rim 15, that is
to say made uniform, as shown in Figure 5.
Next, the ream is pushed with the aid of a pusher
P' (Figure 6) in a direction F', perpendicular to the
entry direction F (Figure 1), on a feed table in order to
feed, for example, a printing machine.
The invention is not limited to the embodiment
described above and illustrated in the accompanying
figures. Its scope extends to alternative embodiments
providing the same functions. By way of non-limiting
examples:
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the cylinder 41 shown in the figures is a cylinder of
revolution, of circumference slightly greater than the
dimension of the sheets of paper. Any other shape of the
directrix (fraction of circle, ellipse, parabola, etc') of
the cylindrical surface providing a difference in radii of
curvature between the first and the last sheet of the ream
may be used;
the rollers 61 and 62 have been shown as solid rollers,
the diameter of which is less than the thickness of the
ream; they may assume other shapes, for example they may
be equipped with transverse grooves enabling air to be
insufflated tangentially to the sheets starting to be
detached;
the rollers 61 and 62 may be actuated by screw jacks,
etc.; their angular movement may be effected by a
multiple-transmission motor or a plurality of independent
motors about coaxial axes; they may be replaced by any
mechanical device enabling a bar to be rolled or to slide
in a continuous movement over the edge of the curved ream;
the pushers P, P' may be replaced by any manipulator arm
or suitable conveyor system.
The person skilled in the art is capable of
developing other alternative embodiments of the device
without departing from the scope of the protection
claimed.
